This invention relates generally to vacuum meat stuffing and relates more particularly to vacuum packaging of a molded meat product in a thermoplastic bag suited for cook-in use.
In vacuum meat pressing, a portion of a moldable raw meat, such as sectioned ham, is pressed while under vacuum into a cooking mold having a generally cylindrical shape, then cooked while in the mold, and thereafter packaged as a pre-cooked compacted meat product. Alternatively, the raw meat may be pressed into a can or fibrous casing. Conventionally, a vacuum meat press refers to a meat press that operates inside a vacuum chamber. In operation, first a moldable raw meat portion is placed inside a stuffing horn within the vacuum chamber, then the chamber is closed and a vacuum drawn, and then a plunger pushes the moldable raw meat through the stuffing horn into a cooking mold initially placed over the discharge end of the stuffing horn. As the mold is filled by advancement of the plunger, the mold retracts from the stuffing horn along a guide that exerts selected resistance to retraction of the mold, such as by a pneumatic cylinder, to yield a selected extent of compaction in the pressed raw meat. THe vacuum chamber is then opened, and the filled mold removed for cooking. Cooking is done usually by immersion in hot water or steam typically at 155.degree.-170.degree. F. for 3-5 hours.
Representatively, such a vacuum meat press is commercially available from Belam B. V. of Uden, Holland. The Belam vacuum meat press has the feature that as the vacuum is drawn, a holding period is allowed to elapse sufficient to deaerate the raw meat before pressing to eliminate residual air pockets within the meat and thereby to produce a sold, cavity free product.
It is the aim of the present invention to provide an improvement in vacuum meat stuffing whereby, concurrent with vacuum stuffing, a raw meat portion is vacuum packaged in a shrink bag suitable for cook-in and shipment of a molded, pre-cooked meat product. Advantageously, such a pre-packaged food product is shipped and marketed, while remaining in its cook-in packaging. A problem in conventional vacuum packaging of molded meat products in thermoplastic bags is incomplete vacuumizing due to entrapped residual air.
The term "cook-in" as pertains to packaging is intended to refer to packaging material structurally capable of withstanding exposure to cook-in time-temperature conditions while containing a food product. The packaging material properly characterized as cook-in will maintain seal integrity and will be delamination resistant under such conditions. The packaging material will also be heat shrinkable under these conditions so as to form a neatly fitting package and preferably should have a tendency toward product adhesion to minimize "cook-out" or collection of fluids between the surface of the food product and the interior surface of the bag.
Of general interest concerning the present invention is the disclosure of U.S. Pat. No. 4,285,980 for "Method For Preparing Molded Poultry Product" issued Aug. 25, 1981 to Lewis, directed to molding and precooking a poultry product using a mold and a flexible bag withing the mold into which poultry meat is flowed followed by closing the bag and cooking the molded poultry by heating the mold.
Of general interest is the disclosure of U.S. Pat. No. 2,779,681 for "Method Of Preparing And Packaging Meat" issued Jan. 29, 1957 to Sell, directed to packaging meat in the ready-to-eat condition by vacuum packaging meat pieces in a shrinkable bag, then shrinking the bag to press the meat pieces contained therein, and then cooking the packaged meat.
Of general interest is the disclosure of U.S. Pat. No. 3,928,938 for "Method For Evacuating Packages" issued Dec. 30, 1974 to Burrell, directed to dual chamber vacuum packaging in thermoplastic bags utilizing in-chamber gathering and clipping apparatus for bag closure.
Of general interest is the disclosure of U.S. Pat. No. 4,043,011 for "Packaging Machines" issued Aug. 23, 1977 to Giraudi et al, directed to an in-chamber gathering and clipping system wherein gathering arms are rotated about a hub and a clip punch is driven to advance a clip from within the hub onto a bag neck gathered by the gathering arms.